Horses sometimes require medicines to be applied to their eyes to treat any one or more of a number of ailments. The treatment can occur several times a day and extend over a period of several days or weeks. Often, a horse will object to the intrusion of the eye by a veterinarian or owner, and can respond with violent or other erratic behavior. For the safety of the owner and the horse, a subpalpebral lavage system is sometimes employed to provide a way of remotely administering the medication to the horse's eye easily and efficiently. The subpalpebral lavage system is made from a flexible tube having two ends, the first end of which mounts a catheter which is passed through the upper eyelid into the upper conjunctival fornix (the space located between the eyelid and the eye). Medication is introduced to the system through the second end of the tube at a second distant injection port and is delivered to the upper conjunctival fornix of the eye through the tubing with the assistance of air injected into the system to move the medication through the tubing to the eye. Upon reaching the end of the tubing in the upper conjunctival fornix, medication exits the system and runs over the eye.
According to present practice, the injection port at the second end of the tube is allowed to hang freely, or the owner may be instructed to tangle the injection port into the mane of the horse. These practices present a variety of problems, including the opportunity for portions of the tube to become caught by a tree branch or other protrusion such as a board, nail, or bucket, and rip the injection port, the catheter, or portions of the tube out of position, causing pain to the animal and requiring reinsertion of the catheter or rearrangement of the tube. Another common problem is that the injection port becomes dirty or is otherwise contaminated by reason of the animal rolling on the ground, which may require cleaning before its reuse, or worse, the dirt or other contaminate may travel through the tube to the injured eye so as to cause infection or introduce a fungus.
Other attempts have been made to address the problems referred to above with other animals including cats, dogs, and mice. One such method is shown in U.S. patent application Ser. No. 2002/0128613 (“Nakayama”), where a somewhat constricting mesh wrap is used to hold the injection port to the back of a small animal such as a cat, dog or mouse. The mesh wrap of Nakayama is however not suited for use on a large animal, such as a horse, and is deemed to be impractical in general due to the natural objection by animals to wearing such a constricting device. Further, the mesh wrap device of Nakayama permits its injection port to be trapped against the body of the animal which encourages contamination due to dirt and sweat being trapped between the wrap and the injection port, which in turn requires removal of the wrap and cleaning of the injection port. A similar item for a horse is known by the tradename Sleazy Sleepwear, however it presents similar problems as described above, with reference to the Nakayama device.
Another attempt to protect the injection port of a medicating device, while not used with an eye catheter, is described in U.S. Pat. No. 5,839,393 (“Rupp”). In this case, a hard plastic shell is employed to protect the injection port from being pulled loose and moved against the animal's body. However, the Rupp device does not keep the injection port clean. Further, use of a device such as the Rupp device is completely impractical on a large animal, since the animal's legs necessarily have to stick through openings in Rupp's hard plastic shell and risk damage.